A recent study conducted by Fu SH and colleagues confirmed that the use of bisphosphonates in patients with osteoporosis and osteoarthritis significantly lowers the risk of total knee arthroplasty, particularly in patients with high adherence and greater treatment span. The study also reported that the use of bisphosphonates reduces the consumption of pain relievers.

Osteoporosis along with osteoarthritis manifests more serious adverse effects on the body than either disease alone. Previous studies have demonstrated the effectiveness of bisphosphonates in the treatment of knee osteoarthritis. However, the studies have limitations in some way or the other. The present study was carried to discover the relationship between bisphosphonate use and risk of total knee arthroplasty along with the pain medication consumption in osteoporotic patients with osteoarthritis.

The osteoporotic patients who were recently affected by osteoarthritis from 2009 to 2012 were included in the study. These patients were selected from the National Health Insurance Research Database in Taiwan and were placed into two groups. Group 1 with 16,276 participants received bisphosphonates, and Group 2 with 123,791 participants did not receive any medication. Further, medication possession ration (MPR) was used to evaluate treatment adherence. The MPR was measured as the proportion of days of bisphosphonate treatment within a fixed duration. An MPR of 80% or more was rated high adherence.

The primary outcome of the study was undergoing total knee arthroplasty, and the secondary outcome was the use of pain medication. Cox proportional hazard models with propensity-score adjustment were used to determine the relationship between the risk of undergoing total knee arthroplasty and bisphosphonate use. This evaluation was done only among one bisphosphonate users group. Although, bisphosphonate association with the consumption of pain medication was evaluated among both groups. Among both bisphosphonate users and nonusers, the incremental change in the mean accumulated defined daily doses of pain medications was calculated.

A total of 16,276 bisphosphonate users and 123,791 nonusers of any anti-osteoporosis drug in patients with osteoporosis who were recently diagnosed with osteoarthritis were recognized. The use of bisphosphonates was considerably linked to a lower risk of total knee arthroplasty. The effect size was higher in patients with a follow-up period of 24 months or longer and an MPR of ≥80%. A significant decrease in pain medication use was noted in bisphosphonate users compared to non-users over the five years of follow-up.